SU739245A1 - Method of lowering silicosis danger of dust - Google Patents

Description

(54) METHOD TO REDUCE SILICOSA. DUSTABILITY

The invention relates to the mining industry and can be used to combat dust in the conditions of underground mining.

There is a known method for reducing the silicicosity of dust by reducing the concentration of dust in the air of the working area 1.

The disadvantage of this method is that their efficiency is not high enough under the conditions of the use of intensive mechanized methods of conducting work that make it difficult to reduce the concentration to the maximum permissible level.

The closest technical solution to this invention is a method of reducing the silicose hazard of dust, which consists in changing the silicogenic properties of the surface of dust particles by treating them with an aqueous solution of calcium oxide 2.

When the dust is wetted with an aqueous solution of calcium oxide, calcium ions are adsorbed on the surface of dust particles, in particular, the most silica-hazardous quartz particles, which leads to a change in the silicogenic properties of dust, a decrease in its biological aggressiveness, and consequently its silica hazard.

The disadvantage of the known method of reducing the risk of silicic danger was that it was not very effective, since the dust, calcium-oxide solution is used to treat dust, sedimentation of the floor or walls of industrial premises or mine workings. However, most recently formed finely dispersed dust remains largely unprocessed due to the low efficiency of the interaction of dust particles in the air-weighted state with solution droplets.

The object of the present invention is to increase the effectiveness of reducing the silicose risk of freshly formed soaring dust.

This is achieved by the fact that the dust is treated with ultraviolet radiation, and the spectrum of the wavelength is 300–380 nm and the intensity is 0.5–5 µW / cm.

Under the action of ultraviolet (UV) radiation in an air atmosphere on the most silica-hazardous component of dust - quartz particles, certain photo-adsorption and photo-desorption processes take place on the surface of the latter. The most likely mechanism for reducing the silicogenic activity of quartz particles in this case is the replacement of the hydroxyls of the free silanol groups Si-OH with oxygen molecules. As a result, the concentration of free silanol groups, which determine the silicogenicity of quartz particles, decreases, and the surface electrochemical potential (Fermi level) of quartz particles changes, and their silicon – silicate properties are also determined.

Example. The silicose hazard of finely dispersed freshly formed quartz dust was reduced in air-weighted condition using UV irradiation with a DRT-375 lamp. The irradiation time was 25 seconds with an average distance from the lamp to a 1 m dust flow. Three irradiated dust samples were obtained under the following conditions: Sample No. 1 - UV intensity 4 µW / cm; Sample No. 2 - UV intensity 0 , 5 µW / cm, sample N ° 3 — radiation was transmitted through a window glass filter 2 mm thick, UV intensity 2 µW / cm. The intensity of radiation was regulated with the help of a diaphragm mounted in front of the lamp. In addition, one sample was obtained of the same, but not irradiated dust.

Dust samples were administered to white rats to females, intratracheally in doses of 50 mg in physiological saline. The intensity of the silicotic process was determined six months after the introduction of dust according to indicators such as the weight of the raw and dry lungs and the content of hydroxyproline, referred to 100 g of the weight of the rat. The data obtained are tabulated.

0 not irradiated

14

20.5

32

The results of experiments on rats show that UV irradiation of dust leads to a pronounced decrease in the intensity of the silicotics process in the lungs compared to unirradiated dust and confirms the absence of a significant effect on the silicogenic properties of UV dust from a wavelength of less than 300 nm that is not transmitted by the filter.

When using UV radiation, a change in the silicogenic properties of the most dangerous freshly formed finely dispersed quartz-containing dust in an air-weighted state in the whole eOMOM volume is achieved. If, in a known method, the effectiveness of reducing the risk of dust's silica risk corresponds to the wetting efficiency of soaring fine particles (less than 5 microns) dust particles and does not exceed 20-30%, then all dust particles in the air are exposed to UV radiation, i.e.

172.0

150.0

50.0 89.0

60.0 84.5

50.0 95.5

3-5 times. The radiation shielding by dust particles is only slightly and noticeably manifested at a dust concentration of 200-300 mg / m and more.

Along with dust, normally dressed people can be exposed as the intensity of UV radiation used is not dangerous to their health. In this case, partial compensation of ultraviolet deficiency will occur, for example, in miners.

Claims (2)

To comply with the safety conditions in the workplaces and industrial premises, the source of UV radiation should be used in a casing protecting it from foreign objects and, if necessary, providing spark-proof and explosion-proof operation. Reducing the ozone concentration formed during operation of the UV source to an acceptable level ensures that the source uses a minimum power sufficient to create the necessary radiation intensity. The invention of the method of reducing the dust's dust risk, consisting in treating dust with means, alters the silicogenic properties of the surface of dust particles, characterized in that, in order to increase the effectiveness of reducing the risk of silicose danger of freshly formed dust, the latter is subjected to treatment with ultraviolet radiation having a wavelength spectrum of 300-380 nm and intensity 0.5-5 µw / cm Sources of information taken into account during the examination 1. USSR author's certificate No. 403864, cl. E 21 F 5/08, 19.07.72. 2. Kaleganov B. A. Electrochemical potential as a criterion for the fibrogenicity of quartz dust. Occupational health and occupational diseases. M., 1978, No. 3, p. 26-31 (prototype).